Terminal clamping device



Sept. 10, 1935. F. s. GREEN 2,013,912

' TERMINAL CLAMPING DEVICE Filed Dec. 1 1952 INVENTORL FLOYD 5 6/VEEN A TTORNE Y.

Patented Sept. 10, 1935 2,013,912 TERMINAL CLAMPING DEVICE Floyd S. Green, St. Louis, Mo., assignor to Frank Adam Electric 00., St. Louis, Mo., a corporation of Missouri Application December 1, 1932, Serial No. 645,149

10 Claims. (Cl. 173-324) This invention relates to terminal clamping devices, and .moreparticularly to an improved clamping mechanism for securing and electrically connecting a terminal portion of an electrical device, such as a cartridge type fuse, to a complementary terminal element of an electric circuit, ortother electrical device to be associated therewi h.

The principal object of the present invention is to provide an improved clamping device, of a particularly rugged and simple structure, which is adapted to efiectively secure, and electrically connect a terminal portion of an electrical device to a terminal contact element of an electrical circuit, or other electrical device, and in which the clamping action is obtained by an eccentric cam mechanism, so formed and assembled as to result in a secure binding and positive electrical contacting of the associated terminal contact elements.

Another object is to provide an improved quick acting terminal clamp device for fuse terminals and the like, in which the clamping or releasing action of the device may be readily and easily effected by a simple actuation of a manual control element through a relatively small angle of rotation.

A further object is to provide a terminal clamping mechanism in which the movable head, or clamping element of the mechanism, engaging the terminal portion of a fuse or other electrical device, is formed to present a resilient terminal contacting portion to compensate for anydifference in the expansion characteristics of different metals, as the terminal engaged by the contacting portion of the clamp mechanism may not be necessarily of the same material as that of the clamp contacting portion of the clamping element.

Further objects and advantages will appear from the following detailed description of the invention, and from the appended drawing, in which:

Fig. 1 is a side elevation of a preferred form of terminal clamping device, as applied to an end terminal of a cartridge type fuse, and a fixed terminal of an electric circuit; Fig. 2 is a side elevation of the preferred form of clamping device in its open, or terminal receiving position; Fig. 3 is an enlarged sectional elevation, as taken along line 33 in Fig. 1; Fig. 4 is an end elevation of the clamping device showing a modification of a portion thereof; Fig. 5 is a side elevation of a modified form of terminal clamp, adapted to receive terminals of cylindrical or ferrule form,

and Fig. 6 is an end elevation of the modified clamp, as viewed from line 66 in Fig. 5.

Referring to the drawing by reference numerals, I designates, generally, a terminal clamp assembly, including an angulate support or base member I2 formed of copper, or any other suitable material having good electrical conducting qualities. An end portion l4 of the base member is provided to seat on any suitable mounting l6, and is secured thereon preferably by a bolt or 10 stud I 8 and nut 20. The stud 18 serves, in addition, to secure in electrical contact with the end portion I4, 2. terminal lug 22 on one end of a con ductor 24, the other end of the conductor being suitably connected to an electrical device (not shown), or associated with an electrical circuit (not shown). The opposite end portion 26 of the support [2 is formed as a contact seat for a terminal end of an electrical device, such as a standard cartridge type fuse, a portion 28 of which is shown in Fig. 1 with its terminal member or blade 30 in contact with the seat portion 26.

A rotary clamping head for holding the terminal 30 in electrical contact with the contact seat 26 will be presently described.

It is to be understood, of course, that the end portion l4 of the base member l2 may be secured directly to a terminal portion of an electrical device, thus eliminating the connector lug 22 and conductor 24, or the end may be modified to form a stationary contact element of an electric switch (not shown).

A clamping mechanism support 32, consisting of a base portion 33, having an extended arm 34 at each end thereof, is secured, as by rivets 36, 35 to a portion 38 of the base member I2, adjacent the end 26 thereof. As shown in Figs. 1 and 3, the arms 34 extend from the base 33 toward the end of the base portion 26, and are provided, adjacent their outer ends, with a bearing aperture 40 40 for a pivot pin or shaft 42 disposed between the arms, the ends 44 of the shaft being extended beyond the arms 34, as best appears in Fig. 3. Pivotally seated upon each shaft end 44 is an eccentric disc cam 46, and a circularly expanded 45 end portion 48 of an arm 50 of a substantially U-shape disc actuating handle or lever 52. Each disc 45, which has asmaller diameter than that of the circular arm portion 48, is centrally positioned on the arm portion, and is secured thereto 50 by any suitable means, such as a rivet 54. As will be noted in Fig. 1, the end of the shaft 42 engages the circular arm portion 48 inwardly of the end thereof, and is radially displaced from the center 56 of the section. The axis of the shaft is preferably offset from and parallel to a plane passing through the centers 56 of the sections 48 and the longitudinal center line of the handle arms 50.

A substantially U-shape terminal clamping member or jaw 58 is provided with a suitable aperture 68 adjacent the end of each of its arms 62 to receive, in the manner of an eccentric strap or follower, one of the aforementioned eccentric cam discs 46. The clamping member 58 is free to rock or oscillate about the disc bearings, between the handle arms 50 and the sides of the contact seat portion 26, to permit ready adjustment between the clamp and the terminal portion engaged thereby and is adapted to be actuated by the discs and operating handle 52, as will be more fully explained hereinafter. The cross member or head portion 64 of the clamp 58 is preferably formed as shown in Fig. 3, to present a large clamping surface, and to give some resilience to the clamping member so as to allow for any difference in expansion between the clamping head and the metallic terminal element engaged thereby. Or, as shown in Fig. 4, the head portion 64 of the clamp 58 may be formed to give a greater flexibility to the head'portion, but at a sacrifice of clamp contacting surface. Of course, it is to be understood that the head portion may be formed in a rigid manner, if it is so desired, but such rigid construction may result in a binding of the clamp and terminal element engaged thereby, which may, in many instances, cause considerable trouble in the removal of the terminal element from the clamping device.

Figs. 5 and 6 illustrate a modification in the terminal clamping device, adapting it to terminal ends of electrical devices which are of cylindrical or ferrule form, suchterminals being found, particularly, in the electrical fuse art. The clamping mechanism support 32 of Figs. 1 and 3, is replaced, in the modified device, by a member 68 secured as by a bolt 10, to one end of a base I2, the other end of the base (not shown) being connected to an electrical devi e, or a conductor' 24 and connector lug 22, as shown in Fig. 1. The end 14 of the member 58 is inwardly, arcuately depressed, as at 16, to form a contact seat'for a cylindrical terminal 18 of an electrical device, such as a. cartridge fuse 80. The member 68 operatively supports a modified clamping element or head 82, and actuating mechanism therefor similar to the mechanism described tacting portion 84 of the clamping head'82 is outwardly expanded in an arcuate manner, corresponding to the arcuate seat portion ,16 of the support 68, to adapt it to the cylindrical terminal I8 of the fuse 80.

In the operation of the clamping device, the jaw elements 58'and 25 are placed in terminal receiving position by operating the handle 52 in a clockwise manner, as illustrated in Fig. 2. As will be understood from the eccentric cam mounting of the clamping element, as the head portion 84 moves away from the terminal seat 26, a, transverse displacement of the clamping element necessarily occurs which moves the element nearer the outer end of the seat portion 26. With the clamping device in open position, the terminal end 30 of the fuse 28 may be inserted between the head portion 64 and the seat 28, in contact with the terminal seat portion. The handle 52 may now be actuated to the left (Fig. 1) to the position shown in the figure, thusbringing the clamping head firmly a sliding movement occurs in a right hand direc- 5 tion (Fig. 1), which results in a clean electrical contact betweeh the head and the terminal, the clamping element serving as an auxiliary electrical conductor to the base member l2. To release the terminal, and hence the fuse device, the 10 handle 52 is actuated to the right (Fig. 2) which lifts the head portion 64 from its clamping engagement with the terminal. A like clamping and releasing actionoccurs with the modified clamping device of Figs. 5 and 6. 15

It is to be understood that the clamping device illustrated in Figs. 1 to 4 may be applied to the terminal ends of electrical bus bars which are of fiat form, and rectangular in cross section,

or to any type of electrical cable or conductor 20 having, at least, a flat terminal end portion. The modified clamp shown in Figs. 5 and 6 may be applied, in a like manner, to the terminal end portion of bus bars or conductors of circular cross section. Although the clamping device is pri- 25 marily adapted to be applied to terminals of electrical devices or conductors, it may be used, with equal effect, in. purely mechanical structures.

The clamping mechanism described herein- 30 above forms a simple, rugged, and durable clamp full intended scope of the invention, as defined in the claims appended hereto.

I claim: I 45 1. In a quick acting clamping device for an electrical conductor, a pair of conductor gripping elements, one of said elements being of hollow form and overlying the other element, av

rockable operating member overlying the said 5 hollow element, pivoted to said other element,

hereinabove and illustrated in Fig 3 The conand plurality of cam discs secured in Spaced relation on said operating member, said discs supporting said hollow element for rockable and shiftablc movement, with respect to said other 55 element. upon manual actuation of said operating member.

2. In a clamping mec anism for a terminal element of an-electrical device, a base including a contact seat for the terminal element, an oper- 60 ating member pivotally carried by said base a resilient clamping element for engaging, said terminal element,-and supporting means for said v I clamping element, said means including a, cam

' element on said operating member, the cam and 65 by said pivot and having a cam element near one end thereof, and a clamping element about said 75 contact-engaging portion, supported by said cam element for shiftable and rockable movement, with respect to said contact-engaging portion, upon actuation of said operating lever.

4. In a, clamping mechanism for a terminal element of an electrical device, a base including a terminal seat, a pair of arms on said base, an operating member pivotally carried by said arms, an eccentric cam disc on said member, and a clamping element operatively supported by said operating member and cam disc for actuation thereby.

5. In a clamping mechanism for a terminal element of an electrical device, a base including a terminal seat portion on one end thereof, arm

members adjacent said seat portion, an operatan electrical apparatus, a base including a ter-- minal contact seat on one end thereof, spaced bearing arms on said base adjacent said contact seat, an operating lever pivotally supported by said arms and having eccentric cam discs in opposed, spaced relation thereon, and a substantially U shaped clamping element having an aperture in each leg portion'toreceive said cam discs, whereby the clamping element is operatively associated with said operating lever for engaging said terminal end.

7. In a clamping mechanism for a terminal element of an electrical device, a base including a terminal contact seat on one end thereof, spaced bearing arms'adjacent said contact seat, a shaft carried by said arms, a U shaped operating lever pivotally mounted on said shaft, said lever having an eccentric cam disc mounted on each leg portion, in opposed relation, and a terminal clamp memberoperatively supported by.

said operating lever and cams, and adapted for movement about said shaft.

8. In a clamping mechanism for a terminal of an electric device, a, base including a terminal contact seat, a pivot on said base, an operating 5 lever carried by said pivot, said lever having eccentric cam discs disposed in spaced relation thereon, and clamping means for said terminal, said means including a resilient clamping head and cam followers operatively engaging said cam discs, said clamping means being associated with said lever and cam discs, for independent pivotal movement thereon.

9. In a clamping mechanism for a terminal of an electric device, a base including a terminal contact seat, a pivot on said base, an operating lever carried by said pivot, a cam carried by said operating lever, and clamping means for said terminal including a cam follower engaging said cam, said clamping means being operatively associated with said cam for independent pivotal movement thereon.

10. In a clamping mechanism for a terminal of an electrical device, a-base of angulate form having a terminal seat portion on one end thereof, a pivot, and a supporting member therefor on said base, said supporting member being disposed adjacent to, and beneath said terminal seat portion, an outer U shaped actuating member having its leg portions seated on said pivot, an eccentric cam disc near the free end of each leg portion of said actuating member, an inner U shaped actuated member having a resilient clamping head portion and having an aperture in each leg portion to receive said cam discs, the apertured legs of said actuated member forming eccentric cam followers, whereby actuation of said outer member is adapted to efiect distance adjustment between said inner member and seat portion, for detachably clamping thereto a terminal of an electrical device.

FLOYD S. GREEN. 

